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Caldera cone metal
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obx hiker
(obxcola) - MLife

Locale: Outer Banks of North Carolina
Caldera cone metal on 03/31/2011 18:20:06 MDT Print View

Nice! Any more photos? I can't figure out the connection from the description.

I decided to google for very small sheet metal brake and came up with this:

Kevin; a program to make/print a template for the screen?

Wow I'm really seriously impressed!

Edited by obxcola on 03/31/2011 18:35:08 MDT.

Kevin Beeden
(captain_paranoia) - F

Locale: UK
re: handle access on 04/01/2011 08:54:18 MDT Print View

Tim & Cola,

Thanks for the compliments.

There are no handles on that MSR Titan; I'd taken them off, and used a pan grab instead. They're now re-fitted, and the handle opening extended. Actually, I use Flissure versions of the clone now, with a horizontal split & joint.

> The folded edge is needed for stiffness.

That's exactly right; in the thinner foils I have access to, the edge tends to bow out slightly. Adding the little triangular fold stops that. In thicker foils such as aluminium roof flashing, the fold may be unncessary, or simply a double thickness.

There are plenty of example clones, of all shapes and sizes, to be found on the Outdoors Magic thread. Fast forward to the last few pages, as the thread's pretty long. Or use the print thread version to see the thread in one go... You can chart the development of the script from an initial throwaway thought, through to what is now a fairly-well refined design tool. And, along the way, I added, and then removed, a mitre joint generator, replacing it with the simpler slot & tab joint which seems perfectly good enough.

The number of script users is almost 100 now... it allows you to create a custom clone for any size pan and burner, and a whole bunch of other esoteric settings. It will generate a horizontally-split clone that will generally fit inside the pan it supports (Flissure option), an inner cone for wood burning (the Infernal option), and my own variant, the Strata ring, which allows the use of one cone with two pans (within reason). The latter is pretty hard to make, but not impossible. For those without a printer, it also displays a "draughtsman's construction", giving the inner and outer radii and horizontal extent, allowing a simple clone to be made by scribing arcs on foil, or on to a template.

PM me with an email address if you'd like the script and instructions document. It's free.

Edited by captain_paranoia on 04/08/2011 07:36:03 MDT.

Tim Zen
(asdzxc57) - F

Locale: MI
Re: re: folding -- location for handle on 04/07/2011 18:53:20 MDT Print View

Kevin -- If the pot has a handle, wouldn't it be better to place the cutout opposite the joint instead of at the joint, which shortens it?

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: re: folding -- location for handle on 04/07/2011 19:09:47 MDT Print View

I'm guessing this method is lighter in weight than having it on the other side.


Kevin Beeden
(captain_paranoia) - F

Locale: UK
re: location for handle on 04/08/2011 07:33:20 MDT Print View


If you're using a folded joint then yes, keeping the joint as long as possible may be good.

But for my slot & tab joint method, I've found that it really doesn't matter where it is, as far as joint strength is concerned, because the interlocked slot and tabs are the same size wherever they are. The joint is usually at least half the depth of the cone, for the pans I've used, anyway; I can imagine a very tall pan with full-height handles might have less, but I don't have any such pans...

The other reason for keeping joint and handle together is that the handle opening provides a natural weak point in the entire structure, and, in stiffer foils that aren't 'encouraged' to hold their shape, the tips of the opening can tend to bow out away from the pan. If the opening and the joint are on opposite sides, you have two weaknesses in the cone circularity. The overlapping of the joint helps to keep this issue under control a little. I also usually keep the handle openings pretty tight, so care is needed when putting the pan in the cone. If the joint were on the opposite side, I'd have to take care not to pop the joint open whilst negotiating the pan into the cone.

It's always best to pre-bend the cone by rolling it up into a tighter cone, so that, when released, it relaxes into just about the right size cone to fit the pan, so that little or no encouragement is needed to make it form the right-sized cone. Concentrate especially on the area around the pan opening, as this is where the cone will tend to bow out, as the conic section is interrupted by the opening.

In the Flissure split version, there's no vertical joint at all in the upper section (which has confused a number of users of the script), so the ends of this must, by necessity, be at the handle opening... I find that the horizontal Flissure joint, when mated, allows the foil to act pretty much like a single piece of foil, due to the overlapping joint, and the conical shape which holds the joint securely in place; once formed into a cone, the Flissure joint cannot be pulled undone, because the base up the upper half conic is a larger diameter than the top of the lower half conic.

Have a play with this idea; you can tell the script to make a very shallow handle opening, and then make one with the required depth, and put the handle openings on the first template. Or you could just use the basic template and draw the opening by hand (shock horror!). You might find it works better than I have.

Edited by captain_paranoia on 04/08/2011 07:39:48 MDT.

Tim Zen
(asdzxc57) - F

Locale: MI
Re: re: location for handle on 04/08/2011 15:58:02 MDT Print View


Thanks for the comments. I used a folded joint. I did the layout using a homemade scribe.

I am using a three cup aluminum coffee pot, which is a heavy for one, but fine for two. Impressive how well it works.

For one person, I think I will use a sierra cup so the stand can be a cylinder instead of a cone.

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: re: location for handle on 04/08/2011 16:08:14 MDT Print View

"I think I will use a sierra cup"

Most Sierra cups are made out of stainless or else titanium. You could try a Cascade cup, but I have never seen them in titanium.


Tim Zen
(asdzxc57) - F

Locale: MI
Re: Re: Re: re: location for handle on 04/08/2011 16:57:26 MDT Print View

Bob -- I found a 750 ml Ti by Vargo. I could probably fry food in one this large. But it is too large for one. Evernew makes one, I think it is around 500 ml. Snowpeak has an aluminum one, but only 11oz (sorry about the mixed units). Anyway, too many choices and I was trying to hold to my gear moratorium.

The cone is a clever idea, but the sierra cup is, what, the dual?

Bob Gross
(--B.G.--) - F

Locale: Silicon Valley
Re: Re: Re: Re: re: location for handle on 04/08/2011 17:06:13 MDT Print View


Wow, 750ml is large for a Sierra cup, but 4.5 ounces of titanium seems like a lot.

Sierra cups have about a gazillion uses. Soup pot, beverage mug, poor mirror, noisemaker for scaring off the bear or for calling folks to dinner, food portion scoop, etc.

I'm not positive if that Vargo cup is deep enough to be efficient on a Caldera. That's why I thought of the Cascade cup shape.


Kevin Beeden
(captain_paranoia) - F

Locale: UK
re: Vargo 750ml? on 04/13/2011 06:14:59 MDT Print View

I've got an Alpkit MyTiMug, which I recall was very similar to a Vargo mug. Not sure if this can be the same as is being discussed here, given the comments about frying and being shallow.

Anyway, here's a pretty picture of the MyTiMug setup, with cosy and pot...

Cookset for Alpkit MyTiMug

Yukio Yamakawa

Locale: Tokyo,JAPAN
Crest with a split windshield on 04/13/2011 12:12:08 MDT Print View




Crest with a split windshield. To all sides, the air supply holes are provided in the form of scales. Occurs simultaneously with the upward rotation of the secondary air supply and air supply by following this one. Around the corner at the bottom of the pot and goes to clash with the blue flame radiates. In this context, the secondary air supply causes the wall of the pot to the fire force vector. Would compensate for the oxygen component is also lacking.
Split crest. It is the exhaust area and earn great benefits, also acceptable to the diameter pot ambiguity. Thin metal plate is also spring-back capabilit

methil alcohol 30ml burn, a cup of 400ml water
hard boiled within 230 seconds with Carbon felt 8g, it looks like a Sushi.

The carbon felt, which floated about 10mm from the floor. I made ​​a wire round the legs. To fit in the direction of evaporation is theoretically justified in burning part of the vertical sides.

Below, which adopted the theory of the bulbous bow, and two cases following description of the air supply. Born to the side effects of hot gas pushes the pot.


Edited by JSBJSB on 04/13/2011 13:04:47 MDT.

David LaRue
(Phaedrus) - F

Locale: Chicagoland
I like the scales on 04/26/2011 06:18:23 MDT Print View

I like the scales and the variable width top with the tabs. I have made a few of these stoves, and the two challenges I have had is pot size (or opening size depending on how you look at it) and getting the right venting. Looks like your design solves both.